Swivel chair mounting



Oct. 27, 1936. n w. F. Hamm 2,058,451

" swIvEr.. CHAIR MOUNTING Filed June 22, 1934 r INVENTOR. WALTER F Hmmm.

Patented Oct. 27, 1936 UNITED STATES PATENT OFFICE ySWIVEL CHAIR MOUNTING Applicationiune 22, 1934, Serial No. 731,847

7 Claims.

The present-invention relates to `an improved swivelchairmounting, and has `for an object to provvide a ball-bearing swivel mounting by means of .which the chair seat may beswiveled `with a 5 very easy action without eiectingfthe vertical adjustment,-and further to provide means by which the chair `seat may be vertically adjusted with facility. A `further object is to provide'adjustment means lwhich may be readily turned to adjust the height of the seat without the necessity for -withdrawing pins, spring -plungers,` or` other such 4locking means, and whichwhen `adjusted will remain in the adjusted position through frictional cooperation-of the parts.

Another object is-to provide a swivel mounting in which lthe swivel support is self-centering so that side play-and looseness is eliminated, and wear is automatically compensated.

Another Objectis to provide a mounting having a vfixed threaded post in whichthe threads are out of Vcontact with the 4rotatable swivel bearing parts.

With the `above and other objects in view an embodiment of the invention is shown'intheaccompanyingdrawing, and this embodiment will be .hereinafter `more fully described with reference thereto, -and the invention will be nally pointed outin the claims.

In the drawing:

Fig. 1 a front elevation of a chair iron'embodying -the invention.

Fig. V2 `ris a top plan View, a'portion ofthe -top flange of one of :the `spider arms being broken away.

Fig. 3 isA a `vertical sectional-view.

Fig. -4 is a sectional plan view-ofthe bearing, taken along the line 4 4 of Fig. 3, the chair iron being removed.

Similar reference characters indicate corresponding parts throughoutthe several gures of the drawing.

vReferring to the drawing,the chair iron illustrated comprisesa lpair of angularcross-section spider arms I--I0 adapted to be screwed to the 45 under side of achair seat in theiusual manner,

and mounted fortilting movement upona support II, which in accordance with the invention ismountedfor vertical adjustment and'swiveling movement. The construction of Vthe `tilting mounting forms no part of the invention, so that it-is sufcient to merely state that the one illustrated comprises a. jointelement of `the type as disclosed in my co-pending `patent application Serial `l\lo.f695,989, led October 31,1933, which Ymaturedinto'Patent No. 2,008,209, issued July 29, 1935, and in which an outer sleeve member I3 is secured `at its ends to the spider arms IU-IU and an intermediate `tubular resilient member I4 of rubber is disposed between them under tension, .and-which normally retains the spider arms 5 in contact with the forward stop I5 of the bracket While permitting tilting movement rearwardly against the inclined stop members Iii-I6.

The support II is provided with a vertically disposed tubular post portion II having an outwardly extending flange I8 at its lower end. A bearing ring I0 is set into the bore of this post nearthe upper end .and the lower end of thebore is beveled, as at 20.

The chair base 2l, which is preferably of the 15 usual type consisting of four radially extending downwardly curved legs, `is provided with a central cylindrical passage l22 in which is engaged and secured the shank of a screw shaft 23, `the lower end of `this shank being reduced, as at 24,

and secured in-theaperture 25 of a plate 26 disposed at the lower side of the chair base by heading over `said `reduced portion, as at 21. The shaft'23 projects upwardly through the aperture 28.` of an apertured plate 29 disposed at the upper 25 side of the chairbase, the plates 21 and 29 being secured by tie rods extending between them through `the chair base.

Therscrew shaft A23 is.provided at its upper end with a plane cylindrical extension portion 23a, 30 which in the 4assembled relation slidably and rotatably engages the bearing ring I9 of the chair iron support, and upon the threaded portion there is engaged an adjustment nut and ball-bearing assembly.

'I'he nut 3| which is in the form of a hand wheel or .knob is internally threaded to engage the threads of the screw shaft and is provided at its upper side with a cylindrical flange 32 forming a pocket33. In the base of this disposed a flat ring washer 34 having a projecting lug 35 Aat its inner periphery which engages a vertically extending key slot 36 in the screwshaft. yA Aball-bearing cup is disposed in the pocket above-the washer 34 and comprises an inner cup member 3l in the form of a ilanged ring carrying a series of anti-frictionballs 38, and an outer cup-member 39, also in the form of a anged ring, and having an inwardly bent lip 40 at its upper edgeextending loosely over the annularzflange 4I of a-bearing ring 42, loosely'disposed about the screw-shaft. The bearing ring has a lower bearing surface 43 tapered upwardly and outwardly and extending laterally at the upper end, which engages the balls in diagonally pocket there is 40 i opposed relation to the cup member 3l which engages the outer and lower sides, and an upper beveled bearing surface 44 upon which the beveled surface 2@ of the chair iron bracket seats. The balls have three point Contact with the surface 43 of the bearing ring 42 and the bottom and side surfaces of the bearing cup 3l, so that the bearing ring is self-centered. As the opening of the ring fits loosely about the threaded portion of the post 23 there will be no frictional or wearing contact therewith `as the chair seat is swiveled. The self-centering bearing ring also automatically compensates for wear.

An upwardly projecting lug i5 formed on the nut 3| is provided with a set screw 46 which projects above the annular flange i8 of the chair iron bracket to retain the latter in assembled relation.

In the normal operation of the mounting the chair iron support and the bearing ring 42 have free swiveling movement about the stationary screw-shaft, the weight of the person seated in the chair pressing the non-rotatable washer 34 tightly between the ball bearing cup members and the base of the pocket 33, so that there is no tendency for the nut to turn. The bearing ring i9 which takes side thrust engages the stati-onary screw-shaft extension portion 23et and therefore has no tendency to impart rotary movement to 4the adjustable parts of the mounting. When the chair seat is being adjusted the weight of the person seated in the chair is removed, so that there is very little friction between the washer and the nut, an-d the latter may therefore be readily turned to adjust the height of the chair.

I have illustrated and described a preferred and satisfactory embodiment of the invention but it will be obvious that changes may be made therein, Within the spirit and scope thereof as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:-

l. In a swivel chair mounting, a chair seat support having a tubular bearing portion having a reduced diameter side thrust bearing portion near its upper end, a chair base, a post secured to said base projecting upwardly having a plane cylindrical upper end portion slidably and rotatably engaging said side thrust bearing porti-on, said post having a threaded portion between said plane cylindrical upper end portion and said chair base, said tubular bearing portion being out of contact with said post below said side thrust bearing portion, an adjustment nut engaged with said threaded portion, annular bearing means carried by said nut at its upper side and engaged by the lower end of said tubular bearing and rotatably surrounding said post, means whereby said tubular bearing is centralized with respect to said annular bearing means, and means whereby said annular bearing means is centralized with respect to sai-d nut.

2. In a swivel chair mounting, a chair seat support having a tubular bearing portion, an annular side thrust bearing ring at the upper end of said bearing portion, of smaller internal diameter than said tubular bearing portion, a chair base, a post secured to said base projecting upwardly and slidably and rotatably engaging said bearing ring, said tubular bearing portion being out of contact .with said post below said bearing ring; said post having screw threads, an adjustment nut engaged with said screw threads, and annular bearing means carried by said nut at its upper side and engaged by the lower end of said tubular bearing portion, said tubular bearing portion and said said nut at its upper side comprising an annular series of ball bearings, means annularly surrounding said balls to limit their outward displacement, and bearing means at the lower end of said tubular bearing portion engaging said balls inwardly of their central line of rotation and pressing them outwardly, said bearing means being centralized with respect to the vertical axis of said tubular bearing portion and adapted through sai-d engagement with said annular series of balls to centralize said tubular bearing portion with respect to said annular series of balls.

4. In a swivel chair mounting, a chair seat support having a tubular bearing portion, a chair base, a post secured to said base projecting upwardly and slidably and rotatably engaging said tubular bearing portion, said post having screw threads, an adjustment nut engage-d with said screw threads, annular bearing means carried by said nut at its upper side comprising an annular series of ball bearings, means annularly surrounding said balls to limit their outward displacement, a bearing ring rotatable about said post supported upon said ball bearings and including an upwardly and outwardly tapered bearing surface adapted to urge said balls outwardly, said tubular bearing portion being supported at its lower end upon said bearing ring, said bearing means being centralized with respect to the vertical axis of said tubular bearing portion and adapted through said engagement with said annular series of balls to centralize said tubular bearing portion with'respect to said annular series of balls.

5. In a swivel chair mounting, a chair seat support having a tubular bearing portion, a chair base, a post secured to said base projecting upwardly and slidably and rotatably engaging said tubular bearing portion, said post having screw threads, an adjustment nut engaged with said screw threads, annular bearing means carried by said nut at its upper side comprising an annular series of ball bearings, a bearing ring rotatable about said post supported upon sai-d ball bearings,

said tubular bearing portion being supported at wardly and slidably and rotatably engaging said tubular bearing portion, said post having screw threads, an adjustment nut engaged with said screw thread, annular bearing means carried by said nut at its upper side comprising an annular series of ball bearings, means annularly surrounding said balls to limit their outward displacement, a bearing ring rotatable about said post supported upon said ball bearings and including an upwardly and outwardly tapered bearing surface adapted to urge said balls outwardly, said tubular bearing portion being supported at its lower end upon said bearingv ring, and means whereby the cooperating engaging surfaces of said tubular bearing portion and said bearing ring are self-centering.

'7. In a swivel chair mounting, a `chair seat support having a tubular bearing portion, a chair base, a post secured to said base projecting upwardly and slidably and rotatably engaging said tubular bearing portion, said post having screw threads and a vertically extending key slot, an

10 adjustment nut engaged with said screw threads,

annular bearingmeans carried by said nut at its upper side comprising an annular series of ball bearings and a bearing ring rotatable about said post supported upon said ball bearings, and engaged by the lower end of said tubular bearing portion, and a locking ring frictionally engaged between said bearing means and said nut having a projection engaging said key slot.

WALTER F. HEROLD. 

